Integrated circuit for controlling switchable current paths

Abstract

An integrated circuit (IC) comprising: control circuitry operable to control: an external switch of a primary current path for an energy storage component of a circuit, wherein the external switch of the primary current path is external to the IC; a first internal switch of a secondary current path for the energy storage element, wherein the first internal switch is internal to the IC, wherein the IC is operable in: a first mode in which the first internal switch of the secondary current path is actuated to enable the secondary current path; and a second mode in which the external switch of the primary current path is actuated to enable the primary current path.

1 . An integrated circuit (IC) comprising:
 control circuitry operable to control:
 an external switch of a primary current path for an energy storage component of a circuit, wherein the external switch of the primary current path is external to the IC; 
 a first internal switch of a secondary current path for the energy storage element, wherein the first internal switch is internal to the IC, wherein the IC is operable in: 
 a first mode in which the first internal switch of the secondary current path is actuated to enable the secondary current path; and 
 a second mode in which the external switch of the primary current path is actuated to enable the primary current path. 
   
     
     
         2 . The IC of  claim 1 , wherein the first internal switch is configured to have a higher on-resistance than the external switch. 
     
     
         3 . The IC of  claim 2 , wherein the first internal switch is physically smaller than the external switch. 
     
     
         4 . The IC of  claim 1 , wherein an on-resistance of the first internal switch is controllable. 
     
     
         5 . The IC of  claim 1 , further comprising a second internal switch of a tertiary current path for the energy storage element, wherein the second internal switch is internal to the IC. 
     
     
         6 . The IC of  claim 1 , wherein the control circuitry is configured to control the external switch and the first internal switch based on signal indicative of a voltage at an energy storage component coupling terminal of the IC. 
     
     
         7 . The IC of  claim 6 , wherein the control circuitry comprises comparator circuitry configured to compare the signal indicative of the voltage at the energy storage component coupling terminal to a signal indicative of a predefined threshold voltage and to selectively actuate the first internal switch and the external switch based on the comparison. 
     
     
         8 . The IC of  claim 7 , wherein the control circuitry is configured to actuate the external switch to enable the primary current path when the voltage at the energy storage component coupling terminal falls below the predefined threshold voltage. 
     
     
         9 . The IC of  claim 8 , further comprising fault detection circuitry configured to output a signal indicative of detection of a fault condition if the voltage at the energy storage component coupling terminal subsequently equals or exceeds the predefined threshold voltage. 
     
     
         10 . The IC of  claim 1 , further comprising fault detection circuitry configured to compare an actual charging or discharging profile of the energy storage component to an expected charging or discharging profile of the energy storage component to identify the existence of a fault condition. 
     
     
         11 . The IC of  claim 10 , wherein the fault detection circuitry is configured to output a signal indicative of detection of a fault condition if a time taken for a voltage at an energy storage component coupling terminal of the IC to reach a predefined threshold voltage does not correspond to an expected time for the voltage at the energy storage component coupling terminal to reach the predefined threshold voltage. 
     
     
         12 . The IC of  claim 1 , wherein the IC is configured to output a fault detection voltage to an energy storage component coupling terminal of the IC and to monitor a voltage at the energy storage component coupling terminal to detect a fault in the external switch. 
     
     
         13 . The IC of  claim 12 , wherein the IC comprises a fault detection voltage source and a fault detection switch configured to selectively couple the fault detection voltage source to the energy storage component coupling terminal. 
     
     
         14 . The IC of  claim 12 , wherein the IC is configured to compare the monitored voltage at the energy storage component coupling terminal to a fault detection voltage threshold voltage and to output a signal indicative of detection of a fault condition if the monitored voltage at the energy storage component coupling terminal is greater than a fault detection voltage threshold voltage. 
     
     
         15 . The IC of  claim 14 , wherein the IC comprises a comparator for comparing the monitored voltage at the energy storage component coupling terminal to the fault detection voltage threshold voltage. 
     
     
         16 . The IC of  claim 13 , wherein the fault detection switch comprises a MOSFET. 
     
     
         17 . The IC of  claim 1 , wherein:
 the IC comprises a first output terminal and an energy storage component coupling terminal, wherein, in use of the IC, a first terminal of the energy storage component is coupled to the first output terminal and a second terminal of the energy storage component is coupled to the energy storage component coupling terminal and the external switch is coupled between the second terminal of the energy storage component and an external reference voltage terminal; and   the first internal switch is coupled between an energy storage component coupling terminal of the IC and an internal reference voltage terminal of the IC, such that in use of the IC the first internal switch is coupled between the energy storage component and internal reference voltage terminal.   
     
     
         18 . The IC of  claim 5 , wherein the second internal switch is coupled between an energy storage component coupling terminal of the IC and an internal reference voltage terminal of the IC, such that in use of the IC the second internal switch is coupled between the energy storage component and internal reference voltage terminal. 
     
     
         19 . The IC of  claim 1 , further comprising:
 second control circuitry operable to control:   a second external switch of a primary current path for a second energy storage component of a circuit, wherein the external switch of the primary current path for the second energy storage component is external to the IC;   a third internal switch of a secondary current path for the second energy storage element, wherein the second internal switch is internal to the IC.   
     
     
         20 . The IC of  claim 19 , further comprising a fourth internal switch of a tertiary current path for the second energy storage element, wherein the fourth internal switch is internal to the IC. 
     
     
         21 . The IC of  claim 1 , wherein the energy storage component comprises a capacitor or an inductor. 
     
     
         22 . The IC of  claim 1 , wherein the IC comprises:
 a power converter IC;   a boost converter IC;   a buck converter IC;   a buck-boost converter IC;   a charge pump IC;   a rectifier IC;   an inverter IC; or   a cell balancing IC.   
     
     
         23 . A module comprising:
 the integrated circuit of  claim 1 ;   the external switch; and   an energy storage component coupled to the integrated circuit and the external switch.   
     
     
         24 . A host device comprising the integrated circuit of  claim 1 . 
     
     
         25 . The host device of  claim 24 , wherein the host device comprises a laptop, notebook, netbook or tablet computer, a gaming device, a games console, a controller for a games console, a virtual reality (VR) or augmented reality (AR) device, a mobile telephone, a portable audio player, a portable device, an accessory device for use with a laptop, notebook, netbook or tablet computer, a gaming device, a games console a VR or AR device, a mobile telephone, a portable audio player or other portable device.